Tundra/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby A boy, Tim, and a robot, Moby, are hiking through a tundra region. Tim reads from a typed letter. TIM: Dear Tim and Moby, Where can I find tundra? Can you please make a movie? From, zgirl. TIM: One movie, coming right up. Moby? MOBY: Beep. Moby films Tim with a hand-held video camera. TIM: There are three types of tundra: Arctic tundra, Antarctic tundra, and Alpine tundra. Arctic tundra is found on the edge of the North Pole, in parts of Greenland, Alaska, Canada, Europe, and Russia. An animated world map shows the location of the Arctic tundra as Tim describes it. TIM: The land is mainly flat, with no trees. In fact, the word "tundra" comes from a Russian term for "treeless plain." MOBY: Beep. TIM: The Arctic tundra formed more than 10,000 years ago, during the last ice age. At the time, huge mountains of ice called glaciers covered much of the northern latitudes. A world map shows the glaciered regions in the northern latitudes. TIM: When the world warmed up, the glaciers retreated, leaving behind the flattened tundra. On the map, the glaciers retreat toward the North and South Poles. TIM: These days, Arctic tundra is covered in ice and snow for seven to eight months of the year. Depending on where they are in the world, the temperatures in the tundra vary, but it's always pretty cold. An animated thermometer appears, displaying the cold temperatures. TIM: In the winters, average temperatures are way below zero, sometimes dipping into the minus 90s. Even during the summer, you'll rarely find temperatures above 50 degrees. Moby begins digging a hole in the tundra ground with a shovel. He hits something hard. MOBY: Beep. TIM: Below the tundra's surface is a layer of soil called permafrost that stays frozen year-round. A cross-section image shows topsoil, with permafrost beneath it. TIM: In the summer, when the surface ice and snow thaws, the resulting water tends to pool. An animation shows the process Tim describes. TIM: This creates temporary ponds and wetlands, where bushes, grasses, and flowers can grow. Moss and lichen also grow, creating a delicate, spongy ground. The animals found on the tundra depend on these plants for food. An animation shows a caribou grazing on a tundra plant. A polar bear pokes up its head behind the caribou. TIM: I guess they also depend on each other for food. All kinds of animals make their home here, including caribou, lemmings, polar bears, rabbits, and wolves. Images show the animals Tim names. TIM: You can also find birds like geese and snowy owls here during the summer, before they fly south for the winter. Even specially adapted black flies and mosquitoes make their contribution to the ecosystem. Images show a goose, a snowy owl, and a fly. MOBY: Beep. TIM: Yeah, even though there's a lot of ice in the Arctic tundra, there's not a lot of snowfall. They're cold deserts, usually with less than 10 inches of precipitation each year. That goes for Antarctic tundra, too. A world map shows the location of the Antarctic tundra, in the southernmost regions of the world. TIM: You would think that Antarctica is completely covered with ice, but the tundra areas have soil that can even support life. Lichens, mosses, and algae do just fine, thanks, on the Antarctic tundra. You can find Alpine tundra all over the world on mountaintops, above the tree line. An image shows a tall, snow-topped mountain with trees far below it. The middle part of the mountain has neither snow nor trees. TIM: Conditions here are harsh, with heavy snowfall and high winds. An animation shows heavy snow. TIM: Still, animals and plants manage to survive here, taking advantage of the two months out of the year when there's no frost. The environment in all types of tundra is extremely fragile. Tracks left by cars and trucks can remain for 30 years or more. An image shows tire tracks on the tundra. A sign next to the tracks reads: 30 years and counting. TIM: So, if you ever find yourself in the tundra, it's best to step lightly. Alright, Moby, let's see that video you shot. MOBY: Beep. Moby holds up both of his hands. They are empty. TIM: You buried it? You buried my mom's camera? MOBY: Beep. TIM: Yeah, I guess that would give you a better view of the permafrost. You don't happen to remember where you buried it, do you? Category:BrainPOP Science Transcripts Category:BrainPOP Transcripts